Abnormal feeding behaviors define human disorders such as anorexia and bulimia, and can lead to the development of chronic disease. Obesity, for example, can result from an imbalance between food intake and energy expenditure, and is associated with increased incidence of diabetes and cardiovascular disease, as well as with reduced quality of life, increased healthcare costs, and premature death. A better understanding of appetite regulation will lead to better methods for controlling food intake, and therefore to better treatments for food-related disorders. The fruit fly, Drosophila melanogaster, is a powerful system for studying the relationship of genes with behavior and disease. Because of the lack of precise tools for measuring fly food consumption, the analysis of hunger, satiety, and the timing of meals has been neglected, despite the possible role played by prandial habits in the physiopathology of obesity, hypercholesterolemia, and diabetes. The goals of this project are to 1) develop simple tools for measuring short- and long-term food consumption in flies and 2) identify and characterize genetic mutants with abnormal feeding behavior. This work will significantly enhance the capabilities of the field and result in expanded use and development of fly models of obesity, feeding, and addiction. How flies make food-based decisions will inform studies on human behavior, and will provide a better understanding of the central mechanisms that underlie appetite and feeding behavior at the genetic and neuronal levels. These discoveries are vital to the development of new therapeutics as well as preventative measures for obesity and other diseases.